Article with protective coating.



- wit ,XR 190989794- SR UNITED s'rarns SAMUEL H. FLEMING, or CLEVELAND,

COMPANY, or CLEVELAND, OHIO,

Parana orrron.

OHIO, ASSIGNOR TO NATIONAL CARBON A CORPORATION OF NEW JERSEY.

ARTICLE WITH. PROTECTIVE COATING.

1,098,794. Specification of No Drawing.

ings forele cjrodes, resistors, furnace bricks and siniilar, articles;

The object of the invention is to produce a hard adhesive, non-porous coating that will stand the high temperatures attained in an electric or other-furnace without burning, or underging other deleterious chemical changes. The manner in which this is accomplished will be given in the accompanying description.

Titanium nitrid is a stable compound even at very high temperatures. It is nonporous, difiicult to break, and is very hard,

'so that it forms an efficient covering for articles of.-carb o n or othgr refractorygmagter ah as it prevent? tlie air or other furnace gases from reaching the carbon or other material to combine therewith.

To form the covering for an article a mix is made of some titanium compound, such as rutile for example, and a suitable binder and this is applied to the surface of the article by any means. The mix may be forced around the article at the same time that the latter is forced, in a manner similar to known process for putting thin shells around arc light electrodes, or it may be ressed on. After the article is coated atitanium compound such as rutile. it is baked at a high temperature in the presence of nitrogen. Titanium has a high affinity for nitrogen and the two readily combine to form the nitrid. By this means 'the coating of titanium oxid or other compound is converted into titanium nitrid.

In some cases it may be desirable to have the article provided with anfixtfilllq i fl. coahangl anjnterior'carbid coat, as the latter would servehs"'iiieansfi'ofinore firmly unite the former to the carbon. Titanium carbid wets the carbon and enters the pores of its exterior surface, so that the union with the carbon is practically perfect.

Letters Patent Patented June 2, 1914.

Application filed October 29, 1912. Serial No. 728,362.

Titanium carbid itself is a poor coating for articles subject to a high temperature in the presence of air, as it readily burns. However, if the coat of titanium carbid is l surrounded by a layer of titanium 'nitrid i it will be protected from the air and will not burn. One of the ways in which these two coats maybe applied to the article is x;

to apply a mix containing titanium and carbon to the article as previously described 5 r and then heat the article with the exclusion of air or nitrogen and thus form titanium carbid from the union of the titanium with the carbon. After the coating of carbid is formed the article is heated in the presence of air or other nitrogen supply and part or all of the titanium carbid is converted into the nitrid. The process can be stopped before the entire coat of carbid is transformed into the nitrid, if an inner coat of titanium carbid is desired.

lVhile I prefer to apply the nitrid coating in the way previously described, I may use another method for forming the coating. The article itself may consist of carbon mixed with rutilc or other titanium compound in the desired proportions. lVhen this is heated the outer surface of the electrodes will be converted to titanium carbid. The carbid coating may be later entirely or partially converted into the nitrid by heating in the presence of nitrogen as previously described, or the article may be first heated in an atmosphere of. nitrogen so that a coating of the nitrld is directly formed.

Having described my invention what I claim is:

l. A refractory article having a coating of titanium nitrid.

A refractory article having one coating of titanium carbid and a second superimposed coating of titanium nitrid.

3. A carbonaceous article, the outer portions of which contain titanium nitrid.

4. The process of forming a coating on an article which consists in applying a layer of rutile and then heating the article in the presence of nitrogen.

5. The process of forming a coating on an article which consists in applying a layer of rutile and carbon, heating with the exduslon of 2111' to change the layer In testimony whereof I have hereunto to tlt-amum carbld, and then heatmg m an slgned my name.

atmosphere of nitrogeq -to form, titanium S AMUEL H FLEMING nitrid. 5 6. A furnace olectroglg conslstmg of car- \Vitnesses:

bon andhavlng'a coatlng of tltanlum nit-rid I. J. ADAMS,

to protect it from oxidation. H. G. GROVER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0." 

